CODEWITHSUNDEEP
delphi
user3164678
user3164678

Reputation: 1

Delphi DLL-use functions designed to return a set of values Integer Record

Currently need to use Delphi to write a DLL, so that the main program calls to the specified place in the removable disk in a file,

Main program designed to VC + +, so use Strut way to call the DLL's data as round!!

Current problems encountered when the main program calls my DLL, the incoming group A Record, and other functions has been dealt with, to return the group B Record,

But using Delphi written DLL, can receive group A Record, but returned group B, but always errors!!

The following is the code for the DLL function, would like to ask if anyone encountered such problems can help point to mention turned a deaf ear

Thanks! !

enter code here
library usbdll;

uses
Windows,
SysUtils,
Classes;

{$R *.res}

Type
p_fin=^TSfin;

TSfin = record //A group of Record is the main program calls incoming Record Type
ST_act:Integer;
pathlen:Integer;//Pass true path length, so that I can get to the far left pathlen, then to remove the rear garbled
Id_hand:Integer;
Id_tail:Integer;

path: PWideChar://The reason why the file path Pwidechar do use guidelines because another branch dll is passed to the main program main program <file path + unicode>, is behind the path and dragging a bunch of gibberish characters

Type
p_out=^TRfout;//B Record is set to return to the main program of the Record Type


TRfout= Record
ST_act:Integer;
ST_move:Integer;
Revis:Integer;
Crchk:Integer;
end;

//The following is my comment out.

// The use of the test in two ways, directly back to the group B Record, does not receive group A Record,A group that does not receive Record, when the main program a call, immediately return the relevant data, the results are normal.

(*

function RFoutEt(test:p_out):Boolean;stdcall;   //ok   Function writing mode

begin

test^.ST_act:=14;
test^.ST_move:=10;
test^.Revis:=12;
test^.Crchk:=8;end;exports RFoutEt;
procedure RFoutE(out Result:TRfout);cdecl;    //ok   Procedure writing mode

begin

Result.ST_act:=14;
Result.ST_move:=10;
Result.Revis:=12;
Result.Crchk:=8;end;exports RFoutEt;
*)

// Actually, I need to charge the main program to my group A Record datain order to deal with post-op, get really want to move the file to specify the true path,and ultimately return to group B Record. 

 function RFoutE(ap_sendin:p_fin;num:Integer):TRfout;stdcall;   //error

 var 
 str_tmp,str_tmp2,temi_diry:string;
 i,copyNum:Integer;

 arr: array[0..100] of Char;

 begin

 //Program by adding the following {} after paragraph, Result is not an empty value is displayed to access illegal address,causing abnormal program termination.

{

StrCopy(arr,Pchar(ap_sendin^.path));  
repeat
str_tmp:=temi_diry;//Use the file path string char array A group referred to in the PWidechar removed 

str_tmp2:=arr[i];
Inc(i);
until i>=ap_sendin.pathlen;

copyNum:=Prs_Filecopy(temi_diry;ap_sendin^.path);//A group of Record with associated data to complete the move of the specified file

}

Result.ST_act:=4;//The following four lines of words alone are able to return data
Result.ST_move:=0;
Result.Revis:=2;
Result.Crchk:=copyNum;end;

PS. Following is a test using VC + + to try more than one function is normal demand

struct Sfin{

int ST_act;       
int pathlen;
int Id_hand;
int Id_tail;
wchar_t *path;
};

struct Rfout{

int ST_act;
int ST_move;
int Revis;
int Crchk;
};

Rfout RFoutE(struct Sfin *a, int num)
{

int ret = 1;
Rfout OutStruct;


copyNum = Prs_Filecopy(temi_diry, inAnow, Anow->path);
ret=1;
if(ret==1){
    OutStruct.ST_act =14;
    OutStruct.ST_move =10;
    OutStruct.Revis = 12;
    OutStruct.Crchk = 8;
    Anow = freeA(Anow);

}   
return OutStruct;   
}

Upvotes: 0

Views: 1047

Answers (1)

David Heffernan
David Heffernan

Reputation: 613461

There is no standard ABI for larger than machine word sized return values. And Delphi uses a different ABI from any other compiler that I've encountered so you'll have no luck returning large records that way.

You'll need to return the record as an out parameter rather than a function return value. Once you make that change, all will be well.

It also looks like your C++ functions use cdecl rather than stdcall.

Upvotes: 1

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